Method and apparatus for preventing offset in printing



T. E. KNOWLTON Oct. 15, 1929.

METHOD AND APPARATUS FOR PREVENTING OFFSET IN PRINTING Filed Feb. 26, 1927 awuewbo'c 7' THEODORE Kxowuron h 5 Que (Mug ries of printing r0 Patented Oct, 15, rare 1,731,467

siren STATES PATENT OFFICE THEODORE E. KNOWLTON, 0F BUFFALO, NEWYORK METHOD AND APPARATUS FOR PREVENTING OFFSET 'IN PRINTING Application filed February 26, 1927. Serial No. 171,175. I

' This invention relates to a method and apfies an inking device for the print roll. While paratus for printing whereby both sides of a I have shown the printing rolls to be horiblank sheet may be printed with characters, zontally disposed, it will be understood that marks, colors, or symbols in clear, distinct this is merely one illustration. They may be outlines without any smearing or blurring vertically disposed or arranged in any other resulting on the previously printed side. desired manner to print alternately on first The invention consists in the novel methone side and then on the other side of the ods, combinations and arrangements hereinsheet without departing from the spirit of after described or claimed for carrying out the invention. 0 the above-stated ob'ect and such other ob- Print roll 3 of the second series of printjects as will hereina ter appear. ing rolls is similar to print roll 2, and is This invention may be readily understood likewise provided with an inking device repby reference to certain exemplifications resented at 7. However, after the blank has thereof described in the following specificabeen printed on one side and is then printed 5 tion. In such exemplifications the sheet to on the reverse side before the. ink has dried, be printed, for example paper, is fed through care must be taken to avoid smearing or any conventional type of printing apparatus blurring of the printed side. It has been cushaving one of the tympan rolls provided with tomary heretofore to run an ofl-set sheet of a roughened circumference. I have illusink repellent material over the tympan roll 20 trated herein onl that part of the printing 5 to avoid destruction or injury to the printapparatus which is utilized to carry the presed side, but this has meet with only partial ent invention into effect. success. Even though the off-set sheet be a In the drawings: v special grade of material, it will not prevent Figure 1 is a view in central vertical secblurring of the outlines or avoid picking up 5 tional elevation of that part of a printing the ink from the sheet while in contact with apparatus embodying my invention; the blank. Because it does take on ink from Figure 2 is a similar view of anothermodithe printed sheet, the ofi-set sheet is unfit for fication; continuous use without imminent danger of. Figure 3 is a similar view of still another injury to the printed matter on the blank. 30 modification; I I have discovered that smearing or blurring Figure 4 represents, on a larger scale, the of the printed side can be avoided by properipheral structure of the second series of viding an oif-set sheet or roll of special conprint and tympan rolls. struction or surfacing the conventional Referring to the drawings, 1 designates a tympan roll with a roughened sheet 8, such as 35 blank sheet which is fed from reel A through emery or sandpaper, or the like, the coated $5 a printing apparatus and then wound upon side being arranged to contac twith the pr nt- 7 reel B or otherwise disposed of after it has ed surface of the sheet while 1t 1S being printbeen printed. Thesheet is printed on both ed on the reverse side. A sheet so supported sides by feeding same in contact with'a se-. while being printing on the reverse side will lls disposed to print first not mar nor blur the already-printed side so on one side and then on the reverse side of nor absorb any ink therefrom. While there the blank. In the illustrative construction, a may be other circumstancescontributing, the series of printing rolls 2 and 3 are horizontheory advanced for this novel result is that tally disposed with the roll 2 arranged to theprinted sheet is supported at a myriad 45- print the sheet on the bottom side and the of points or ridges 9 (Fig. 4), thereby preprint roll 3 arranged to print the sheet on venting the 1nk from being squeezed lat the reverse side. Roll 4 is a conventional erally over the surface of the blank, or if any tympan roll cooperating with the printing negligible amount of ink is squeezed laterally roll 2 to support the sheet while the printed when any of the type 10 presses against the -50 matter is beingimparted thereto, and 6 typiblank directly above the points or ridges, 10o

, emery or sandpaper, or the like, appear in i or the like.

irregular arrangement, however, they might be arranged uniformly or irregularly, such as directly on the face of..the tympan roll by providing cross vertical or diagonal grooves If a paper facing is used on the tympan roll, it could be tightly clamped or fastened in any well known manner about the face of the roll 5 as shown in Fig. 1. The modification in Fig. 2 shows the roughened supporting sheet as an endless belt 12 circumvolved over the tympan roll 5 and one or more idlers 13 and 1%.

I The modification in Fig. 3 shows the roughened supporting sheet 15 being traversed from feed roll 16 over the tympan roll 5 to a winding roll 17, after which it may be used over and over again.

Obviously, the present invention is not restricted to the particular embodiments herein shown and described, neither is it necessary that all the features of the invention be used conjointly, since they may be employed advantageously in various combinations and sub-combinations.

'Having described preferred embodiments of my invention, I claim:

1. A method of preventing offset in printing characterized by printing a blank sheet upon one face, supporting the sheet on a dry rough surface, and then printing the sheet on the reverse side.

2. A method of preventing ofiset in printing characterized by printing a blank sheet upon one face, supporting the sheet on a dry ridged surface, and printing the sheet on the reverse side while same is supported on the ridged surface.

3. A method of concomitantly printing a blank sheet on opposite faces comprising feeding a sheet in contact with a printing element, traversing a dry ridged support in contact with the sheet, and feeding the sheet in contact with a printing element while supported on said support to print the reverse side of the sheet.

4:. A method of concomitantly printing a blank sheet on opppsite faces comprising feeding one face of asheet in contact with a printing roll, traversing a dry serrated support with the sheet, and printing the reverse face of the sheet while .on the serrated upport.

5. A methodof preventing oflset in printing a blank sheet on opposite faces comprising printing one face ofthe sheet, supporting the sheet on the printed face over a dry serrated surface, and simultaneously printing the reverse face. 7

6. The method of preventing offset in printing a blank sheet on opposite faces come prising first. printing one face of the sheet, traversing the sheet in contact with a dry mineral surfaced roll, and simultaneously printing the reverse face.

, 7. The method of successively printing opposite faces of a continuously'traversing sheet and supporting said sheet on a dry serrated surface to receive the subsequent print.

8. Printing apparatus comprising a series of printing rolls disposed to print on oppo-' site faces of a sheet, tympan rolls cooperating with the printing rolls, and a dry serrated means cooperating with the print roll which prints the reverse face of the sheet.

. 9. Printing apparatus comprising a series of printing elements disposed to print ,alterter described, means for printing one face of a traversing sheet, means for printing the reverse face of the sheet, and a dry serrated oil'- set roll cooperating with the second printing means.

12. In a printing apparatus of the character described, a printing and tympan roll for printing one face of a sheet, a printing and tympan roll disposed to print the reverse side of the sheet, and a dry mineral-coated means traversing with the second tympan roll to contact with the printing face of the sheet.

13. A print ng apparatus of the character described comprising a printing device, a platen associated with the printing device, and means having a dry irregular surface cooperating with the platen to support a printedl blank while being printed on the reverse s1 e.

14. A printing apparatus comprising a printing device, a pla en associated with the printing device, and a facing for the platen provided with dry irre lar surface to support a printed blank w ile being printed on the reverse side.

'15. A platen means for a printing apparatus havin a dry irregular surface on which a printe' sheet is adapted to be supported while being rinted on the reverse side.

16. A met 0d of preventing offset in print- 'ing characterized by printing a blank upon one face, supporting said blank on a platen which supports the blank while with the printed side in contact with emery paper, and printing the reverse side while in contact with said emery paper. 1

17. Brinting apparatus comprising a series of printing rolls disposed to print on opposite faces of a blank, tympan rolls cooperating with the printing rolls, and a facing of emery paper surrounding the tympan r011 being printed on the reverse side. a 1

18. A platen means for a, printing apparatus haying a facing of emery paper on which a printed sheet is adapted to be supported.

In testimony whereof, I aflix my signature.

THEODORE E. KNOWLTON.

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